`@universal-middleware/sirv` as optional peer dependency

[rtritto]

@universal-middleware/sirv should be an optional peer dependency because of Vercel or other use cases

[magne4000]

Have you had any issue with it?
It shouldn't do anything if deployed on Vercel, but it allows users to benefit from it otherwise without having to manually install it (which is one of the purpose of vike-photon).

[rtritto]

No, I haven't any issue but I need to reduce the dependencies size.
@universal-middleware/sirv isn't used by all use cases so it must be handled as external and optional dependency; there isn't any sense of installing it every time, even if it will not be used.
All vike's components should be minimalist and, on occurence, they may be extendend with the install of vike's components or the install of optional dependencies.

[magne4000]

Closing as not planned for now, but it will certainly be part of a refactor at some point